Adjustable ladder.



No. 665,238. Patented 1an. l, |901.-

Wg P. LIBBY. ADJUSTABLE LADDER.

(Application tiled Oct. 24, 1900.) udo Modal.)

Nimes STATES ATENT Fries?.

WILLIAM P. LIBBY, OF SOMERVILLE, MASSACHUSETTS.

ADJUSTABLE LADDER.

SPECIFICATION formingpart of Letters Patent No. 665,238, dated January 1, 1901.

Application filed October 24:, 1900. Serial No. 34,120. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM P. LIBBY, a citizen of Canada, residing at Somerville, in the county of Middlesex and State of Massachusetts, have invented new and useful Improvements in Adjustable Ladders, of which the following is a specication.

This invention relates to improvements in adjustable ladders; and it is adapted for use as an adjustable extension-ladder, as an adj ustable step-ladder, either ou a horizontal or inclined plane or on stairs, also as an adjustable trestle for use by masons, painters, and interior decorators, or as an adjustable staging, as well as for other similar purposes, as may be desired.

'Ihe invention is carried out as follows, reference being had to the accompanying drawings, wherein- Figure l represents a perspective view of the invention, showing it in use as an adjustable step-ladder. Fig. 2 represents an enlarged partial front elevation of one side of the ladder and the adjusting device thereon. Fig. 3 represents an end view of Fig. 2. Fig. 4. represents a cross-section on the linee 4 shown in Fig. 3, and Fig. 5 represents a vertical section on the line 5 5 shown in Fig. 2.

Similar letters refer to similar parts Wherever they occur on the different parts of the drawings.

A A and B B represent the side rails of the two ladders, which are pivotally connected and adjustably secured by my improved device, Which will hereinafter be described.

a a are the rounds or steps on the ladder A, and b b are similar rounds or steps on the ladder B, as usual in devices of this kind.

To the upper ends of each of the side rails B is secured a serrated disk C, having teeth on its inner side adapted to engage with a similar serrated or toothed disk D, having made integral with it a guide D', in which the side rail A is longitudinally adjustable, as shown.

The serrated disks C and D are adapt-ed to be interlocked by means of a screw-threaded bolt el, attached to or made integral with the serrated disk D. Said bolt passes through a perforation in the disk C and is provided with a thumb-nut d', which when tightened causes the serrated disks C and D to be interlocked.

The guide D is provided With a thumbscrew E, preferably loosely connected to a shoe F, adapted to bear against the rail A when the thumbscrew E is tightened, as shown in Figs. 4 and 5.

In using the device as a step-ladder, as shown in Fig. l, the thumb-nut d is lirst loosened sufficiently to enable the ladders A and B to be spread apart at their lowerends, as may be required, after which said thumbnuts are tightened, causing the serrated disks C D to be interlocked, so as to prevent the said ladders A and B from spreading.

If the step-ladder is to be used on uneven ground or on stairs, I loosen the thu rnb-screws E E sufficient-ly to permit the rails A A to be adjusted up or down in the guides D' D', and after being so adjusted I secure the said rails A A within the guides D D' by tightening the thumb-screws E E, as shown in the drawings.

The device may be used as an extensionladder by first loosening the thumb-nuts d' d and swinging the rails A A upward about in a line with the rails B B, after which said thu mb-nuts are tightened, so as t0 cause the serrated disks C D to be intel-locked and secured together.

rlhe device is capable of a variety of adjustments for various purposes,amoug which may be mentioned its employment as an adjustable trestle for use by masons, painters, and interior decorators, and it may also be used as an adjustable staging and for other similar purposes, as may be desired.

The device is very simple in construction, is readily adjustable for various uses, and provides a very strong and rigid connection between the ladder portions after said parts have been adjusted in the desired position, as hereinabove described.

What I wish to secure by Letters Patent and claim is- 1. The com biuation with a pair of ladders, of a serrated disk secured to each of the side rails of one of the ladders, a guide adj ustably secured to each of the side rails of the other of the said ladders, and means formed integral with said guide and meshing with said disk to permit of securing said ladders at variable inclinations.

2. The combination with a pair of ladders, of a serrated disk secured to each of the side IOC rails of one of the ladders, a guide adj ustably secured to each of the side rails of the-'other of said ladders, a serrated disk formed integral with said guide and meshing with the first-named disk to permit of securing said ladders at variable inclinations and means for securing said disks together.

3. The combination with a pair of ladders, of a serrated disk connected to each ofthe side rails of one of the said ladders, a longitudinally-adjustable guide secured to each of the side rails'of the other ladder, means for securing said guidein position, a serrated disk formed integral With the lsaid guide and adapted to mesh with the first-named disk, [5 to permit of securing said ladders at variable inclinations, and means for connecting the said disks together.

In testimony whereof I have hereunto set my hand in presence of two subscribinfblr Wit- 2o nesses.

WILLIAM P. LIBBY.

Witnesses:

ALBAN ANDREN, RICHARD C. ULBRICH. 

